Particulate polycyclic aromatic hydrocarbons in rural households burning solid fuels in Xuanwei County, Southwest China: occurrence, size distribution, and health risks.

The study is about the size distribution and health risks of polycyclic aromatic hydrocarbons (PAHs) in indoor environment of Xuanwei, Southwest China particle samples were collected by Anderson 8-stage impactor which was used to gather particle samples to nine size ranges. Size-segregated samples were collected in indoor from a rural village in Xuanwei during the non-heating and heating seasons. The results showed that the total concentrations of the indoor particulate matter (PM) were 757 ± 60 and 990 ± 78 µg/m3 in non-heating and heating seasons, respectively. The total concentration of indoor PAHs reached to 8.42 ± 0.53 µg/m3 in the heating season, which was considerably greater than the concentration in the non-heating season (2.85 ± 1.72 µg/m3). The size distribution of PAHs showed that PAHs were mainly enriched in PMs with the diameter <1.1 µm. The diagnostic ratios (DR) and principal component analysis (PCA) showed that coal and wood for residential heating and cooking were the main sources of indoor PAHs. The results of the health risk showed that the total deposition concentration (DC) in the alveolar region (AR) was 0.25 and 0.68 µg/m3 in the non-heating and heating seasons respectively. Throughout the entire sampling periods, the lifetime cancer risk (R) based on DC of children and adults varied between 3.53 ×10-5 to 1.79 ×10-4. During the heating season, the potential cancer risk of PAHs in adults was significant, exceeding 10-4, with a rate of 96%.

Persulfate-based remediation of organic-contaminated soil: Insight into the impacts of natural iron ions and humic acids with complexation/redox functionality.

The use of persulfate (PDS) for in-situ chemical oxidation of organic contaminants in soils has garnered significant interest. However, the presence of naturally occurring iron-containing substances and humic acid (HA) in environmental compartments can potentially influence the effectiveness of soil remediation. Thus, this study aimed to investigate the role of key functional groups (adjacent phenolic hydroxyl (Ar-OH) and carboxyl groups (-COOH)) in HA that interact with iron. Modified HAs were used to confirm the significance of these moieties in iron interaction. Additionally, the mechanism by which specific functional groups affect Fe complexation and redox was explored through contaminant degradation experiments, pH-dependent investigations, HA by-products analysis, and theoretical calculations using six specific hydroxybenzoic acids as HA model compounds. The results showed a strong positive correlation between accessible Ar-OH and -COOH groups and Fe3+/Fe2+ redox. This was attributed to HA undergoing a conversion process to a semiquinone-containing radical form, followed by a quinone-containing intermediate, while Fe3+ acted as an electron shuttle between HA and PDS, with Fe3+ leaching facilitated by generated H+ ions. Although the stability of HA-Fe3+ complexes with -COOH as the primary binding sites was slightly higher at neutral/alkaline conditions compared to acidic conditions, the buffering properties of the soil and acidification of the PDS solution played a greater role in determining the Ar-OH groups as the primary binding site in most cases. Therefore, the availability of Ar-OH groups on HA created a trade-off between accelerated Fe3+/Fe2+ redox and quenching reactions. Appropriate HA and iron contents were found to favor PDS activation, while excessive HA could lead to intense competition for reactive oxygen species (ROS), inhibiting pollutant degradation in soil. The findings provide valuable insights into the interaction of HA and Fe-containing substances in persulfate oxidation, offering useful information for the development of in-situ remediation strategies for organic-contaminated soil.

Qualitative determination of volatile substances in different flavored cigarette paper by using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with chemometrics.

In order to investigate the difference of volatile substances among flavored cigarette paper, which are supplied by several manufacturers with different batches, the stability of the complex system of scented cigarette paper was analyzed and evaluated. In this study, Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was used to detect the aroma compounds of 23 flavored cigarette paper samples. Based on fingerprint analysis, the differences and changes of aroma compounds of different samples were studied in the form of data visualization. Principal component analysis, partial least squares regression analysis, cluster heatmap analysis and artificial neural network analysis were used to evaluate the stability of different cigarette paper. The results show that: A total of 29 volatile substances were identified from different scented cigarette paper. Fingerprint analysis revealed that the volatile substances of different cigarette paper samples were roughly the same, but not the content. The results of chemometrics analysis showed that there were significant differences in the characteristic aroma compounds of cigarette paper from different manufacturers. HS-GC-IMS technology combined with chemometrics method could be applied to determine the difference of volatile substances among different flavored cigarette paper, which theoretically and technically supported the quality stability maintenance and identification of flavored cigarette paper processed in different places.

An evaluation of the population characteristics, semen quality, and utilization status of autologous sperm cryopreservation and fertility preservation in for 662 patients: a 6-year monocentric retrospective study.

BACKGROUND: Sperm cryopreservation is an effective method of fertility preservation for disease-related and social sperm freezing. In total, 662 subjects (range: 15-65 years-of-age; mean: 33.49 ± 8.79 years-of-age) were included in this study to investigate the population characteristics, semen quality, and usage of autologous sperm preservation patients in Beijing. Of these, 351 were cancer patients (53.02%, 31.14 ± 7.32 years-of-age) and 311 were non-cancer patients (46.98%, 36.14 ± 9.54 years-of-age). RESULTS: We found that the number of preservation cases increased steadily from 2015 to 2019; 89.73% of these had a bachelor's degree or above; 54.83%, 41.54%, and 3.63% were single, married, and divorced, respectively. The cases of cancers and oligozoospermia accounted for 71.30% of all patients; therefore, most patients required fertility preservation due to disease. The cancer group had a significantly lower sperm concentration, rate of progressive sperm after the frozen-thawed test, total progressive motility sperm count after the frozen-thawed test, and recovery rate of progressive motile sperm (RRPM) than the non-cancer group (all P < 0.05). Sperm count-related parameters were significantly affected by testicular cancer, while sperm motility-related parameters and RRPM were significantly affected by leukemia. The utilization rate of preserved sperm was 6.34% after 6 to 78 months of follow-up. In terms of fresh or frozen embryo transfer, the clinical pregnancy rate was 56.76% or 50.00%, and the live birth rate was 24.32% or 21.43%, respectively. CONCLUSION: The need for autologous sperm preservation was dominated by patients with diseases, followed by the need for social sperm freezing. Tumors had a major negative impact on semen quality, and the usage rates of stored semen were at lower level compared to the number of sperm cryopreservation. Medical staff and patients should pay attention to both cognition-action consistency and cost-effectiveness in fertility preservation.

RéSUMé: CONTEXTE: La cryoconservation des spermatozoïdes est une méthode efficace de préservation de la fertilité pour la congélation des spermatozoïdes liée à des causes médicales et aux demandes sociétales. Au total, 662 hommes (entre 15 et 65 ans; moyenne: 33,5 ± 8,8 ans) ont été inclus dans cette étude pour évaluer les caractéristiques de la population, la qualité du sperme et l'utilisation de la préservation autologue de spermatozoïdes réalisée par des patients à Beijing. Parmi ceux-ci, 351 étaient des patients atteints de cancer (53%; 31,1 ± 7,3 ans) et 311 des patients non atteints de cancer (47%; 36,1 ± 9,5 ans). RéSULTATS: Nous avons constaté que le nombre de cas de conservation a augmenté régulièrement de 2015 à 2019; 89,7% d'entre eux avaient un baccalauréat ou plus; 54,8%, 41,5% et 3,6% étaient respectivement célibataires, mariés, ou divorcés. Les cas de cancer et ceux d'oligozoospermie représentaient 71,3% de tous les patients; par conséquent, la plupart des patients avaient besoin d'une préservation de la fertilité pour raison de maladie. Le groupe des hommes atteints de cancer avait significativement une plus faible concentration de spermatozoïdes, un plus faible taux de spermatozoïdes progressifs après le test de congelation-décongelation, un plus faible nombre total de spermatozoïdes de motilité progressive après le test de congelation-décongelation, et un plus faible taux de récupération de spermatozoïdes mobiles progressifs (TRMP) que le groupe de patients non atteints de cancer (tous p < 0,05). Les paramètres liés au nombre de spermatozoïdes ont été significativement affectés par le cancer du testicule, tandis que les paramètres liés à la mobilité des spermatozoïdes et le taux de récupération de spermatozoïdes mobiles progressifs ont été significativement affectés par la leucémie. Le taux d'utilisation des spermatozoïdes conservés était de 6,3% après 6 à 78 mois de suivi. En ce qui concerne le transfert d'embryons frais et congelés, le taux de grossesse clinique était respectivement de 56,8% et 50,0%, et le taux de naissances vivantes respectivement de 24,3% et 21,4%. CONCLUSIONS: Le besoin de conservation autologue des spermatozoïdes était dominé par les patients atteints de maladies, suivi par le besoin social de congélation des spermatozoïdes. Les tumeurs ont eu un impact négatif majeur sur la qualité du sperme, et le taux d'utilisation des spermatozoïdes stockés était à un niveau inférieur à celui du nombre de cryoconservation des spermatozoïdes. Le personnel médical et les patients doivent prêter attention à la fois à la cohérence cognition-action et à la rentabilité de la préservation de la fertilité.

Enhancive and inhibitory effects of copper complexation on triplet dissolved black carbon-sensitized photodegradation of organic micropollutants.

Excited-triplet dissolved black carbon (DBC) was deemed as a significant reactive intermediate in the phototransformation of environmental micropollutants, but the impacts of concomitant metal ions on photochemical behavior of excited-triplet DBC (3DBC*) are poorly understood. Here, the photolytic kinetics of sulfadiazine and carbamazepine induced by 3DBC* involving Cu2+ was explored. The presence of Cu2+ reduced the 3DBC*-induced photodegradation rate of sulfadiazine; whereas for carbamazepine, Cu2+ enhanced 3DBC*-induced photodegradation. Cu(II)-DBC complex was formed due to the decreasing fluorescence intensities of DBC in the presence of Cu2+. Cu2+ complexation caused the decrease of 3DBC* steady-state concentrations, which markedly reduced 3DBC*-induced photodegradation rate of sulfadiazine due to its high triplet reactivity. Kinetic model showed that 3DBC* quenching rate by Cu2+ was 7.98 × 109 M-1 s-1. Cu2+ complexation can also enhance the electron transfer ability, thereby producing more ∙OH in Cu(II)-DBC complex, which explains the promoting effect of Cu2+ complexation on carbamazepine photodegradation in view of its low triplet reaction rate. These indicate that 3DBC* reactivity differences of organic micropollutants may explain their photodegradation kinetics differences in DBC system with/without Cu2+, which was supported by the linearized relationship between the photodegradation rate ratios of ten micropollutants with/without Cu2+ and their triplet reaction activity.

Interfacial interaction between benzo[a]pyrene and pulmonary surfactant: Adverse effects on lung health.

Inhaled polycyclic aromatic hydrocarbons (PAHs) can directly interact with the lung surfactant (PS) lining of alveoli, thereby affecting the normal physiological functions of PS, which is a serious threat to lung health. In spite of the extensive study of benzo[a]pyrene (BaP, a representative of PAHs), its potential biophysical influence on the natural PS is still largely unknown. In this study, the interfacial interaction between PS (extracted from porcine lungs) and BaP is investigated in vitro. The results showed that the surface tension, phase behavior, and interfacial structure of the PS monolayers were obviously altered in the presence of BaP. A solubilization test manifested that PS and its major components (dipalmitoyl phosphatidylcholine, DPPC; bovine serum albumin, BSA) could in turn accelerate the dissolution of BaP, which followed the order: PS > DPPC > BSA, and mixed phospholipids were significantly responsible for the solubilization of BaP by PS. In addition, solubilization of BaP also enhanced the consumption of hydroxyl radicals (·OH) in the simulated lung fluid, which could disturb the balance between oxidation and antioxidation.

Formation Process of Silicate-Iron Oxyhydroxide Complex and Its Influence on the Distribution of Heavy Metals in Mining Area.

Silicate-iron oxyhydroxide complex formed by mineral weathering has an important influence on the geochemical reactions of heavy metals in mining areas. In this work, tailings were collected from an abandoned iron tailings pond, and the physicochemical properties and distribution of heavy metals were studied under natural weathering and hydraulic processes. The results showed that Fe2+ in the iron tailings were transported to the surface during the weathering process, and then the iron oxyhydroxide formed by mineralization adsorbed Cu2+ and Zn2+. Silicic acid and exchangeable acid were released during the formation of binary agglomerates between hydroxy iron oxide and kaolin, then they migrated to the lower area of a tailing pond via surface runoff. Finally, silicate-iron oxyhydroxide complex were formed. The heavy metals were replaced by H+ and penetrated to the bottom layer with water. This research provides an important scientific basis for the prevention and control of heavy metal pollution in mining areas.

Interaction of industrial smelting soot particles with pulmonary surfactant: Pulmonary toxicity of heavy metal-rich particles.

Inhalable particles can influence the interfacial behavior of pulmonary surfactant (PS) resulting in various pulmonary diseases. However, the effects of actually airborne particles on the interfacial behavior of PS and its role in the alteration for soluble metal fraction in particles are entirely unexplored. Herein, we investigated the interaction of PS extracted from porcine lungs with smelting soot fine particles as a model of inhaled heavy metal-rich particles. Our results showed that the phase behavior and foamability of PS were obviously altered in the presence of smelting soot fine particles. In addition, the soluble heavy metals in smelting soot fine particles notably increased in the presence of PS as compared to that of saline solution. Further experiments conducted by adding PS's major components (dipalmitoylphosphatidylcholine, DPPC; bovine serum albumin, BSA) demonstrated that comparison of DPPC, adsorbed BSA is beneficial for the dissolution of heavy metals in smelting soot fine particles. Dynamic light scattering experiments verified that the well dispersion of smelting soot fine particles in the presence of BSA may be responsible for the higher solubility of heavy metals. These findings indicate that PS's interfacial behavior change and PS-enhanced solubilization release of metal components may increase the potentially pulmonary risk in the exposure of airborne fine particles enriched with heavy metals.

Reversible Solubilization of Pyrene by a Gas Switchable Surfactant Investigated by Molecular Dynamics Simulation.

The reversible solubilization behavior of pyrene by a CO2/N2 switchable surfactant (named N'-dodecyl- N, N-dimethylacetamidinium bicarbonate (DDAB)) was investigated with molecular dynamics (MD) simulations. We first individually simulated the aggregation of the inactive surfactant N'-dodecyl- N, N-dimethylacetamidines (DDA) and effective surfactant DDAB in water. Detailed structural properties analysis showed that DDAB molecules aggregated into a micelle, while the aggregation of DDA molecules was considered to be an oil droplet that was separated from the water phase. MD simulations revealed that pyrene molecule was solubilized in the interior hydrophobic region of the micelle as expected. Pyrene was adsorbed on the surface of the oil droplet which is due to the dense packing of DDA molecules inside the oil droplet. The simulated release process showed that the solubilized pyrene in the interior was squeezed out when the micelle was changed to an oil droplet. Reduced density gradient (RDG) function was used to study the weak interactions and explore the molecular driving force behind the reversible solubilization. The results demonstrated that repulsion effects of water molecules on the DDA headgroups play an important role on the pyrene release. Because of the persistent molecular motion of DDA molecules into the droplet center, pyrene was finally repelled out of the oil droplet. Our study provided a molecular mechanism into the reversible solubilization of a gas-controlled switchable surfactant. This is expected to be useful for surfactant-enhanced remediation (SER) experiments.